Remove Driver::UseStdLib.

All but one place are checking options::OPT_nostdlib instead of looking at
this field, so convert that one other place to doing that as well.

No behavior change.

llvm-svn: 308848
diff --git a/clang/lib/Driver/ToolChains/NetBSD.cpp b/clang/lib/Driver/ToolChains/NetBSD.cpp
index a1a3108..e89ee37 100644
--- a/clang/lib/Driver/ToolChains/NetBSD.cpp
+++ b/clang/lib/Driver/ToolChains/NetBSD.cpp
@@ -324,7 +324,7 @@
 
 NetBSD::NetBSD(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
     : Generic_ELF(D, Triple, Args) {
-  if (getDriver().UseStdLib) {
+  if (!Args.hasArg(options::OPT_nostdlib)) {
     // When targeting a 32-bit platform, try the special directory used on
     // 64-bit hosts, and only fall back to the main library directory if that
     // doesn't work.